NAMPT and idiopathic pulmonary fibrosis: Several experimental models have found that lung fibrosis may be significantly modified by modulating these genes; in particular, reductions in NAMPT expression facilitate IPF myofibroblast apoptosis and lead to protection from fibrosis in vivo [62], whereas overexpression of PAI-1 enhances lung fibrotic responses [63,64,65,66,67,68,69,70].